Process of making chemically treated activated adsorbent material



`Aug. 11, 1931. s, BAYLls I 1,818,453 v PROCESS OF MAKING CHEMIGALLY TREAT-ED ACTIVATED AI'DSORBENT MATERIAL Filed Aug. .'50, 192'?v 4 Sheets-Sheet 1 (E 1l I g (x3 g n N lb N El W f N N.

Aug. ll, 1931. w. s. Ezmfms/I 1,818,453` PROCESS'OF MAKING CHEMICALLY-TRETED ACTIVATED ADSORBENT MATERIAL `FiledlAug. .'50, 1927 Y 4 Sheets-Sheet 2 Aug. 11, 1931.

W. S. BAYLIS PROCESS 0F MAKING CHEMICALLY TREATED ACTIVATED ADSORBENT MATERIAL Filed Aug. 30, 1927 4 Sheets--Sherefl 3 @Qu QQ kok@ Aug. -11, 1931. w. s. BAYLls 1,318,453

PROCESS OF MAKING CHEMICALLY TBEATED ACTIVATED ADSORBENT MATERIAL Filed Aug. l3o.- 192'1 4 sheets-sheet 4 not completely remove this lime.

Patented Aug. l1, 193717..v

UNITED STATES PATENT CFFI'CE WALTER S. BAYLIS, 0F LOS ANGELES, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, T0 FILTROL COMPANY,'0F CALIFORNIA, A CORPORATION OF CALIFORNIA PROCESS OF MAKING CHEMICALLY TREATED ACTIVATED ADSOEBENT NIAJ'EERIAL Application filed August 30, 1927. Serial No. 216,350. I

My invention relates to adsorbent clays, such as fullers-earth, and particularly to a chemically treated activated adsorbent mineral which is useful in many industries for removing impurities from liquids or gases.

Almost all raw clay from which the activated adsorbent mineral is kmade contains lime in some form. This lime is not usually present in the form of lime oxide CaO, but in the form of calcium carbonate CaCO3, and silicate of lime CaSiOa. It has been my experience that this lime. is mov'e from the clay and consequently the activated adsorbent mineral manufacturer does Experiments have shown that an activated adsorbent mineral having no lime content is at least 30% more eiiicient than activated adsorbent material having a lime content.

It is one of the important objects of this invention to provide a method of making activated adsorbent mineral which is free from lime or lime salts.

In the ordinary method of manufacture of activated adsorbent mineral the raw clay is first acid treated and then washed to remove the impurities which have been freed from the clay. I have found that if the lime has not been throughly removed from the clay, the clay will during washing very slowly give 'up the acid which has combined with it.

This results in instability and reversions, and prevents a uniform reactivation of the used activated adsorbent mineral.

It is one of the objects of my invention to provide a 'method of making activated adsorbent mineral which 'will not give up the combined acid during the process of manufacture.

A further objectof the invention is to pro.- vide an activated adsorbent mineral which will be stable and 'which may be reactivated uniformly to a high efliciency. y

I have found that a better activated adsorbent mineral may be produced if all of the lime or at least a very large percentage of the i limecontentis removed from the raw clay before it is subjected to the acid treatment.

It is accordingly one of theobjects ofl this invention to provide a method of making an quite difficult to reactivated adsorbent mineral in which the lime is removed before the clay is acid treated.

Experiments have shown that the treatextent and no more; and thatif the certain limit is exceeded, the product will ynot have the desired qualities.

It is .one of the objects of the invention to provide a method of making activated adsorbent mineral in which the action of the acid is quickly stopped when the clay has been treated to a certain degree.

I have further found that a better and more uniform activated adsorbent mineral may be made if the rawlclay is successively treated with different amounts of acid. y

It is one of the objects of this invention to provide `a method ofv adsorbent mineral in which the raw clay is successively subjected to the action of acid treatments of different amounts of acid.

I Other objects and advantages will appear in the following description.

My invention may be conducted by using various types of apparatus which are capable of performing functions which are necessary. In the following description of the invention, reference will bev had to the accompanymaking activated i The different units'of this apparatus can all be purchased on the market and are Well kncwn the industry. lFor this reason the diagrammatic drawings will/be suicient, I since anyone versed in the art will readily vunderstand/the apparatus.

The raw;.`r clay is first mined, being preferably broken up into lumps of about walnut size orr smaller. This mined raw clay is first vaged orw'eathered by exposing it to the atmosphere and sun for a period of time. This aging process produces some change in the raw clay which is -not thoroughly understood.

- drawings, and the remainder of the process of producing the activated adsorbent mineral is carried on. The raw clay in lump form is delivered to a crusher 11 in whichthe raw clay isk finely divided. This ray clay passes from 'the crusher 11 throu h a chute 12 to an ele;

v'ator 13, by means .o which it is delivered to a drier 14. In this drier 14 the clay is subjected to aheat treatment which seems to make it more succeptible to the following steps in the process. The4 clay is preferably heated to a temperature above the boiling point of water and below the sintering point of the cla In this manner the clay is thoroughly drled. The dry clay is delivered from the drier 14 to a storage bin'15.

The next step in the process is to treat the clay with a brine solutlon. The clay is delivered through a conduit 16 to an agitator 18 having an agitating means 19 therein. This clay is thoroughly agitated with a brine solution which is a solution of sodium chloride supplied thereto by means of -a pipe 20. Dif- I' ferent gradesof clay will require dilferent proportions and concentrations of brine, and anyone skilled in-the art will be able to readily determine the desired proportions and concentrations. The brine solution and the clay are thorou hly mixed together until the bn'nesolution as thoroughly removed the lime or lime salts lfrom the pores of the e of clay and brine solution is ldelivered .through a conduit 21 to a thickener 22 or other suitable apparatus for separating ,the brine'solution from the clay. The clay tends to settle tothe bottom of the thickener 22, and the brine solution4 to the top, being withdrawn through a ipe 23. In the thickener 22 the mixture o clay and Abrine solution'is agitated b an agitator 24 and simultaneously therewith softened water is intro'- duced through apipe 25. .I prefer to use softened water because softened water has no lime content which would tend to de osit its lime in the clay and thus tend to de eat the purthe clay pose fthis step of the'process. YThe concentration of the brine solution is graduall reduced so that there is but a slight trace o salt in the mixture. A greater portion of the lime and lime salts are carried from the clay through the pipe 23.

The washin action of the clay which takes place in the t ickener 22 does not entirely remove all traces of the brine and lime or lime salts from the-clay. It is very essential that all traces be removed. This partly washed clay is delivered through a conduit 26 to a rotary filter 28 by means of a pump 27 in the conduit 26. The rotary filter 28 may be the standard Oliver filter, well known in the industry. This filter 28 includes a tank 29 into which the clay is' delivered. The clay is drawn onto the drum 30 of the filter 28 and all of the moisture is removed therefrom by a vacuum on the interior of the drum. Softened water is sprayed onto the cake formed on the 37 to a second Oliver ilter 39. This second Oliver filter 39 has a tank 40 into which the mixture is delivered and a drum 41 on which a cake is formed. The moisture is withdrawn from the cake by a vacuum, and the cake is sprayed with softened water by a pipe 42. The dry cake is removed from the drum 41 by a scraper 43 and is delivered to a second agltator 44 having an algitating means 45. The clay is at this time t oroughly mixed by the action of the a itating means 45 with a hot softened water lntroduced through a pipe 47,. I prefer to use hot water at this point in the process but cold softened water may be used with slightly inferior results.

When the clay has been treated to the extent described, about ofthe lime or lime salts originally contained in the raw clay has been removed. When a cla has but a small lime content, the action of t e sulphuric acid is such as to produce a better product.

The next step in the process is to acid-treat with sulphuric acid. The acidtreating apparatus illustrated consists of a series of treating tanks 50 .which are connected together by conduits 51 in such a manner that the overflow from one tank will pass into the next succeeding tank.V Each tank is provided with a pipe 52 for introducing steam thereinto, a pipe 53 for introducing agitating air thereinto, and a pipe 55 for introducing acid.

The clay is forced through a conduit 57 from the agitator 44 to the first tank 50 by means of a centrifugal pump 58,. In the first tated. The steam tends to boil the mixture,"

and it is found that this boiling action increases the effectiveness of the acid. After treatment in the first tank for a short period of time the mixture is overfiowed into the second tank where it is mixed with a fresh supply of acid. Treatment is carried on in this second tank for a certain length of time and the mixture is then passedto the third tank. In the diagrammatic sketch, five acid-treating tanks are illustrated. Each succeeding tank is preferably hotter than the preceding tank, and in each succeeding tank the mixture is preferably mixed with a larger amount of acid. This is found to be the most effective way of acid-treating the clay and is found to produce the best product. The clay usually passes through the acid-treating tanks in seven to nine hours. The action of the acid on the clay is to remove from the pores of the clay certain undesirable substances such as aluminum oxide, magnesium oxide, etc., converting these oxides into soluble salts so that they may be Washed out. If there is any lime in the clay at this time, this lime will be converted into calcium sulphate which is an inactive substance. It will be seen that if the clay is not treated enough, all'of these oxides and lime will not be removed from the clay.

As pointed out in the statement of invention the clay must not be over-treated. By properly gauging the time and proportioning the amount of acid added during the acid treatment, the clay will be treated to the limit when it passes from the last tank 50.

The next step in the process is to quickly stop the acid action so as to prevent overtreatment of the clay. This is accomplished in a stop-treatment agitator -60 to which the treated clay is delivered by a conduit 61. The clay ismixed with hot softened-Water supplied to the stop-treatment agitator by a pipe 62 and is thoroughly and violently agitated by compressed air supplied through a pipe 63. Steam is supplied to the agitator 60 through a pipe 64 and the mixture of clay and hot softened water is boiled during agitation.

This treatment is effective in completely stopping the action of the sulphuric acid, andthe clav will not be over-treated.

. The lime which is converted into calcium sulphate is first converted into a flocculent or amorphous condition, and if it is washed out while in this form or condition, it can b more readily and more thoroughly removed than if it is allowed to crystallize into an ab- 65 soluble either in ot or cold water. I find solute calciumjsul hate which is not readily it advantageous to charge the washing waterV of the stop-treatment agitator 60 with a suitable xing medium, such as carbon dioxideCOz, which may be introduced through a p1pe 66. The carbon dioxide fixes the lime 1n a flocculent state and prevents crystallization. c i

It is very essential to the method that the acid liquor be removed from the clay as quickly as possible after the stopping action. This quick separation is best accom lished by means of a centrifuge 67 to whlch the mixtureis delivered through a conduit 68. Th1s centrifuge separates the clay and acid liquor, delivering the clay through a conduit 69 and the acid liquor through a pipe 70. The clay passing through the conduit 69 has a liquid content of less than 15%. Since it is impossible to remove all traces of the acid liquor and the impurities which are carried in it, it is necessary to further wash the clay. The clay is delivered by the conduit 69 to an agitator 71 having an agitating i means- 72 which thoroughly mixes the clay with hot softened water introduced into the agitator'71 by means of a pipe 73. The clay is quite thoroughly Washed by the hot softened water and the acid liquor in greatly diluted. i

This mixture is delivered through a conduit 74 by means of a pump 75 to an apparatus for finally Washing it. This apparatus consists of a series ofy Oliver filters 77, each of which ters 28 and 41, having a tank 78, a. drum 79, a scraper 80, and a pipe 81 for delivering hot softened Water to the cake formed on vthe drum. Placed between the filters 77 are agitators 82 having an agitating means 83 and pipes 84 for delivering hot softened Water is substantially the same as the lthereto. The mixture passes from the agi- Vtator 7l into the first filter .77 Where it is formed in a cake on the drum 79 and de- Watered by the suction in the drum. At the upper part of the drum hot softened Water is sprayed onto the cake, which Water replaces any moisture which was in it. The dry cake is removed from .the right part of the drum has been converted into an activated adsorbent mlneral and has desirable ities, all of the lime and other foreign matter having 4 been removed therefrom, and thel clay bein combined with a proper amount of acidl w ich gives it its desirable decolorizing qualities.

In thedrier 86 which may be a rotary kiln,

purifying qual- 1 Vas shown, the clay is completely dried for subsequent sacking. The clay is delivered from the drier 86 to a cooler 87 in which the temperature ofthe clay is reduced fi'om a high temperature to about atmospheric temperature. From the cooler 87 the clay is delivered by an elevator 88 to a storage bin 89, from which storage bin 89 the clay is delivered to a- Raymond mill 90 in which final grinding takes place. The clay is withdrawn from the mill 90 by a blower 91 and delivered to a dust collector 92, the clay being separated from the air which carries it to the dust collector. From the collector 92 'the clay drops to a sacking apparatus indicated by the numeral 93. This completes the entire process, commencing with the mining of a raw clay and terminating with the sacking of the activated adsorbent mineral.

In the foregoing description, as I have pointed out before, I have described the process in connection with certain standard apparatus without any intention of limiting myself. The various time elements and proportions of treating mediums for various ades of clay are determined more or less y experimenting rst with a small quantity of clay. This knowledge is peculiarly within the province of those skilled in the art and therefore need not be pointed out herein. It will be seen that no set of tem eratures or proportions would apply to all c ays. I have also described a complete process which produces a very superior activated adsorbent mineral from a very inferior raw clay. If a better rade of raw clay is to be treated, it is possi le to dispense with some of the steps in this process; therefore, in the appended claims various phases of the process will be claimed individually and separately.

As an example, if a clayis found having no lime content or an exceedingly small lime content, the brine solution treatment may be eliminated. In some instances the clay is of such a nature that the drying of it to remove the water may be dispensed with.

The very important features of the inven-o tion reside in the means for removing the lime or lime salts from the clay, the particular manner in acid-treating the clay, and the abrupt stopping of the acid action after the acid treatment has been finished. The method by which the clay is washed at certain times during the process and the use of softened water or lime-free water are very important to the invention.

I claim as my invention:

1. A method of preparing an activated adsorbent clay comprisingzfsubjecting the raw clay to the action of the atmosphere; trea'ting said clay with sulphuric acid to render soluble certain impurities thereof; and washing said clay with softened water to remove said impurities and any uncombined acid.

2. A method of preparing an activated adl.

sorbent clay comprising: subjecting the raw clay to the action of the atmosphere; treating said clay with a sodium chloride solution to remove certain impurities therefrom and then substantially removing the water and substances dissolved therein.`

3. A method of preparing an activated adsorbent clay comprising: finely dividing said ing the water and substances dissolved there- 5. A method of preparing an activated adsorbent clay comprising: finely dividing said raw clay; heating said clay to remove largely the water of crystallization; treating said mineral with a sodium chloride solution to remove certain impurities therefrom and then substantially removing the water and substances dissolved therein.

6. A method of preparing an activated adsorbent clay comprising: treating the finely divided clay with a sodium chloride solution; separating said sodium chloride solution from said clay; and treating said clay with sulphuric acid.

7. A method of preparing an activated adsorbent clay comprising: removing the water content from the linelv divided clay; treating the finely divided clay with a sodium chloride solution; separatin said sodium chloride solution from said c ay; and treating said mineral with sulphuric acid.

8. A method of preparing an activited adsorbent vclay comprising: treatin the finely divided clay with a sodium chlori e solution; treating said clay with strong sulphuric acid; and immediately thereafter stopping the actiox of said sulphuric acid'by diluting said aci 9. A method of preparing an activiated adsorbent cla comprising: removin the water content rom the fine y divided c treatly thereafter stopping the action of 'said sulphuric acid. e

10. A method of preparing an activated adsorbent clay comprising: treatin the finely divided clay with a sodium chlori e solution then removing said solution; treating said clay with strong sulphuric acid' and unmediately thereafter treating said clay with sof.-

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tened water to stop the action of said sulphuric acid.

11. A method of preparing an activated adsorbent clay com rlsing: treating the linely divided clay with) a salt solution; separating said salt solution from said clay; -treating said clay'with sulphuric acid; and immediately thereafter treating said clay with softened water forstopping the action of said sulphuric acid.

12. A method of preparing an activated adsorbent clay comprising; treating the finely divided clay with a sodium ch oride -solution; treating said clay with sulphuric acid; and immediately thereafter treating said clay with carbon dioxide and water free from the bases which it is desired to eliminate from the clayfor stoppingv the action of said sulphuric acid.

13. -A method of preparing an activated ad- 15. A method of preparing an activated clay which comprises: heating a raw'clay to a temperature in excess o f the boiling point of water but below the smtering point of saidclay'for a suiiicient period to thoroughly dry the clay; treating the dry clay with a sodium chloride so1ut1on; removing the major part of said solution; treating the heated clay with sulphuric acid; and washing the clay to remo-ve water soluble matter therefrom. Y

16. A method of preparing an activated adsorbent clay which comprises: treating the raw finely divided claywith a sodium chloride solution; then thickenin the clay and treating it with a strong sulp uric acid solution; diluting the mixture o clay and sulphuric acid with softened water and carbon dioxide;

and boiling and agitating the resultingmixture. y

17. A method of preparing an activated clay which com rises: treatin finely divided clay with sulp uric acid an `washing said treated clay with water charged with carbon dioxide.

18. A method of improving the quality of an activated cla which comprises: treatin the clay with treatment by vigorous a waterwhich is free from movingl certain undesirable 'tation wit e salts; and reconstituents ofimmediately thereafter phuric acid; arrestin si said clay by washing with water containing carbon dioxide.

19. A method of preparing an activated adsorbent earth comprising: dlviding the raw earth into lumps of walnut size or smaller; exposing them to the weathering action of the sun and .open atmosphere for. thirty days or longer; ,then treating said earth with sulphuric acid to changey the microstructure thereof and tov render soluble certain bases therein; and then washing said treated earth with water suliiciently to remove substantially entirely said solubilized bases and Iany uncombined acid.

20. A method of preparing an activated clay adsorbent which comprises dividing the raw clay into lumps of walnut size or smaller; subjecting the clay in action of the sun and open atmosphere for not less than thirty days; then treating said clay with sul huric acid to render soluble certain bases t erein and to change the microstructure of the clay; and then washing said mineral with water substantially free from the bases which it is desired to eliminate from -the clay to remove said bases and any uncombined acid.

Inl testimony whereof2 I have hereunto set my hand at Chicago, Illinois, this 23d day of August, 1927.

WALTER S. BAYLIS.

such a condition to the Patent No. 1,818,453. vGrimma August 11, 1931, to

' WALTER s, BAYLIs.

ted specification of the Page 4, line 92, claim and that the said It is hereby certified that error appears in the prin above numbered patent requiring correction as follows: 5, a11d line 108, claim 7, for the word "mineral" read clay;

Letters Patent should be read with these corrections therein that the :ame may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of September, A. D. l93l.

M. Moore,

(Seal) Acting Commissioner of Patents. 

